The present chapter applies the p-model to two stages of the development of German phonology in order to exemplify the role of inconsistency in theory change. It focuses on a detailed case study on the Basic Inconsistency of German Affricates. After the problem and its subproblems have been raised in , in , our analyses will show why Wurzel’s () eclectic framework, applying both terms of structuralist phonology and of Chomsky and Halle’s The Sound Pattern of English, yields a p-inconsistency without an acceptable p-resolution. In , we will examine whether Prinz and Wiese’s () CV phonology could avoid the shortcomings of this approach. In , we will draw conclusions from the case study that suggest generalisable methodological guidelines for the future treatment of inconsistency in linguistic theorising. Finally, in , we will answer the question of how the permanent interplay of the emergence and the resolution of inconsistencies shapes the development of linguistic inquiry.